Light Emitting Diode (LED) is a solid semiconductor luminous device, which uses a solid semiconductor chip as a light emitting material and releases surplus energy by means of recombination of charge carriers, thus leading to photon emission and directly generating light like red, yellow, blue, green, cyan, orange and purple light.
Today, as energy shortage is increasingly serious, some developed areas, such as Japan, United States and Europe, are making efforts to use LEDs for public lighting in urban areas. Meanwhile, our government also encourages the development in LED and semiconductor illuminating industry. Therefore, the semiconductor lighting industry is likely to have a bright prospect in the international and domestic markets.
With the development of LED technology, LED lighting devices have been used in various applications. The LED lighting devices may be classified in different types, such as, ordinary LED, digit tube LED, high-power LED, and so on. Generally, the high-power LED may include a plurality of LEDs connected in-series. An alternating current from an AC power goes through a rectifier circuit, which is then supplied to the plurality of LEDs, so that the plurality of LEDs can emit light.
However, the conventional LED circuit needs a special rectifier circuit to transform an alternating current into a direct current which can be supplied to the LED circuit. In addition, in the conventional art, the LED circuit can not work even if only one LED is damaged.